Widely known as the “forever chemicals,” PFAS are among the most stubborn contaminants facing scientists today. These compounds are so stable that they can persist in water supplies, ecosystems, and even the human body for decades. Because of their persistent actions, PFAS contamination is a growing environmental and public health concern around the world.
Now, researchers have discovered important clues that could help improve efforts to eliminate these chemicals.
New clues in the fight against PFAS contamination
New research shows that PFAS can be broken down using intense light without adding chemicals. More importantly, the researchers identified the key process that causes the failure.
The researchers found that hydrogen radicals, highly reactive particles produced from water when exposed to ultraviolet (UV) light, play a central role in the destruction of PFAS molecules.
This finding challenges previous thinking about how PFAS degradation occurs. Previous studies have mainly focused on other reactive species as the main drivers of the process. By pinpointing hydrogen radicals as the dominant force, scientists now have a clearer picture of the chemistry involved.
This understanding is important because knowing exactly what causes PFAS destruction can help researchers develop more effective treatment techniques.
How hydrogen radicals permanently decompose chemicals
Hydrogen radicals are highly reactive and can attack PFAS molecules. The process gradually removes fluorine atoms and breaks down the compound into smaller substances that are less persistent in the environment.
The researchers also discovered that this reaction works best under high-energy ultraviolet light, particularly at wavelengths below 300 nanometers.
Associate Professor Zhong-Su Wei from Aarhus University, who led the research, said the discovery provides valuable guidance for future technology development.
“PFAS are known to be very stable due to strong bonds between carbon and fluorine, and breaking that bond is a major challenge. By identifying hydrogen radicals as the key driver, we now have a clearer direction on how to design more efficient and sustainable technologies to actually destroy these chemicals, rather than just remove them,” he says.
Beyond PFAS removal to PFAS destruction
Wei points out that many current approaches do not truly solve the PFAS problem. Instead, they often transport chemicals from one location to another.
“Currently, many technologies can filter PFAS from water, but they cannot completely remove them. The real goal is degradation, breaking down the molecules completely. Understanding the mechanisms is essential if we want to achieve that in an environmentally friendly and scalable way.”
Researchers caution that this new finding is not an immediate solution. The decomposition process remains relatively slow, and intermediate compounds can form as the chemical decomposes.
Still, identifying the main factors behind the response represents an important advance. This discovery provides scientists with important information that will help accelerate the development of more effective PFAS treatment technologies.
Ultimately, this study suggests that even some of the world’s most persistent pollutants could become vulnerable if researchers understood their chemistry well enough to be able to target them directly.
What are PFAS?
- PFAS (per- and polyfluoroalkyl substances) are a large group of synthetic chemicals that have been used since the 1940s.
- These are found in products such as waterproof clothing, food packaging, firefighting foam, and nonstick cookware.
- These are sometimes referred to as “eternal chemicals” because they break down very slowly in the environment.
- PFAS can accumulate in water, soil, wildlife, and humans
- Exposure has been linked to health concerns such as cancer, liver damage, and hormonal disorders.
- Most existing water treatment technologies can remove PFAS, but not destroy them.
